Volume control for optimum television stereo separation

• US 5,054,071 A
• Filed: 02/03/1989
• Issued: 10/01/1991
• Est. Priority Date: 02/03/1989
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta Incorporated (Cisco Systems, Inc.)
• Inventors: Bacon, Kinney C.
• Primary Examiner(s): Isen, Forester W.
• Application Number:
  US07/306,010
• Time in Patent Office: 970 Days
• Field of Search: 381/1, 381/10, 381/11, 381/12, 381/104, 381/109, 358/144, 358/197, 358/194.1, 455/4, 455/232
• US Class Current: 381/12
• CPC Class Codes: H04N 7/102 Circuits therefor, e.g. noise reducers, equalisers, amplifiers H04N7/108 takes precedence

Abstract

Volume control for use in a cable television set top converter or the like is calibrated for optimum television stereo channel separation. The volume control controls the volume to predetermined levels. One of the predetermined levels is a particular level calibrated for optimum stereo separation. An indicator on the converter indicates the optimum stereo separation volume level. When an internal VCR timer turns on the set top converter, the set top converter is forced to the optimum stereo separation volume level. The calibration is performed during manufacture and ensures that the indicated volume level for optimum stereo separation is indeed the optimum volume level.

Claims

1. Apparatus for use in a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels and a particular level provides optimum stereo separation, the apparatus comprising:

a demodulator for demodulating an input signal to provide an aduio signal;

a user interface for inputting a desired volume level;

a volume control for varying the volume of the audio signal in accordance with the desired volume level and outputting a volume controlled audio signal, the volume control including a trimming control calibrated for a volume that provides optimum stereo separation when the desired volume level is at the particular level and the volume that provides optimum stereo separation has unity gain; and

an indicator for indicating when the volume level of the audio signal provides optimum stereo separation.

2. Apparatus for use in a cable television converter for controlling the gain of a signal, wherein said gain is controlled to predetermined levels and a particular level attains an optimum condition, the apparatus comprising:

a user interface for inputting a desired gain level;

a gain control for varying the gain of the signal in accordance with the desired gain level; and

a trimming control connected in series with the gain control, the trimming control set to calibrate for a gain that attains the optimum condition when the desired gain level is at the particular level.

3. The apparatus of claim 2, further comprising a demodulator for demodulating the signal prior to control of gain by the gain control.

4. The apparatus of claim 2, further comprising:

a timer for enabling the apparatus at a preprogrammed time; and

a controller for setting the gain control to the particular level that attains the optimum condition, the controller setting the gain control to the particular level attains the optimum condition when the apparatus is enabled by the timer.

5. Apparatus for use in a cable television converter for controlling the gain of a signal, wherein said gain is controlled to predetermined levels and a particular level attains an optimum condition, the apparatus comprising:

a user interface for inputting a desired gain level;

a gain control for varying the gain of the signal in accordance with the desired gain level; and

an indicator for indicating when the gain level of the signal attains the optimum condition.

6. The apparatus of claim 5, further comprising a trimming control connected in series with the gain control, the trimming control calibrated for a gain that attains the optimum condition when the desired gain level is at the particular level.

7. The apparatus of claim 5, wherein the particular level attaining the optimum condition has unity gain.

8. The apparatus of claim 5, further comprising a demodulator for demodulating the signal prior to control of gain by the gain control.

9. The apparatus of claim 8, further comprising a modulator for modulating the gain controlled signal.

10. The apparatus of claim 5, further comprising a controller for setting the gain control to the particular level that attains the optimum condition.

11. The apparatus of claim 10, further comprising a timer for enabling the apparatus at a preprogrammed time, the controller setting the gain control to the particular level that attains the optimum condition when the apparatus is enabled by the timer.

12. The apparatus of claim 10, wherein the optimum condition includes nearly optimum signal-to-noise ratio and distortion.

13. The apparatus of claim 10, wherein the particular level for attaining the optimum condition has unity gain through the apparatus.

14. Apparatus for use in a cable television converter for controlling the gain of a signal, the gain is controlled to predetermined levels and a particular level attains an optimum condition, the apparatus comprising:

a user interface for inputting a desired gain level;

a gain control for varying the gain of the signal in accordance with the desired gain level;

a trimming control coupled with the gain control, the trimming control set to calibrate for a gain that attains the optimum condition when the desired gain level is at the particular level, wherein the optimum condition includes optimum stereo separation, and the gain that obtains said optimum condition has unity gain.

15. The apparatus of claim 14, wherein the optimum condition further includes nearly optimum signal-to-noise ratio and distortion.

16. Apparatus for used in a cable television converter for controlling the gain if a asignal, said gain is controlled to predetermined levels and a particular level attains an optimum condition, the apparatus comprising:

a user interface for inputting a desired gain level;

a gain control for varying the gain of the signal in accordance with the desired gain level;

a trimming control coupled with gain control, the trimming control set to calibrate for a gain that attains the optimum condition when the desired gain level is at the particular level, wherein the optimum condition includes optimum stereo separation; and

a modulator for modulating the gain controlled signal.

17. Apparatus for use in a cable television converter for controlling the gain of a signal, wherein said gain in controlled to predetermined levels and a particular level attains an optimum condition, the apparatus comprisng:

a user interface for inputting a desired gain level;

a gain control for varying the gain of the signal in accordance with the desired gain level;

a timer for enabling the apparatus at a preprogrammed time; and

a controller for setting the gain control to the particular level that attains the optimum condition, the controller setting the gain control to the particular level that attains the optimum condition when the apparatus oe enabled by the timer.

18. The apparatus of claim 17, further comprising a demodulator for demodulating the signal prior to control of gain by the gain control.

19. The apparatus of claim 18, further comprising a modulator for modulating the gain controlled signal.

20. Apparatus for use in a cable television converter for controlling the gain of a signal, said gain is controlled to predetermined levels and a particular level attains an optimum condition, the apparatus comprising:

a user interface for inputting a desired gain level;

a gain control for varying the gain if the signal in accordance with the desired gain level;

a timer for enabling the apparatus at a preprogrammed time;

a controller for setting the gain control to the particular level that attains the optimum condition, the controller setting the gain control to the particular level that attains the optimum condition when the apparatus is enabled by the timer, wherein the optimum condition inlcudes optimum stereo separation.

21. The apparatus of claim 20, wherein the particular level for attaining the optimum condition has unity gain through the apparatus.

22. The apparatus of claim 20, wherein the optimum condition further includes nearly optimum signal-to-noise ratio and distortion.

23. A method for use in cable television converter apparatus for controlling audio volume, wherein said audio volume is controlled to predetermined levels and a particular level provides optimum stereo separation, the method comprising the steps of:

demodulating an input signal to provide an audio signal;

inputting a desired volume level;

varying the volume of the audio signal in accordance with the desired volume level and outputting a volume controlled audio signal wherein the volume that provides optimum stereo separation has unity gain; and

incidating when the volume level of the audio signal provides optimum stereo separation.

24. A method for use in cable television converter apparatus for controlling audio volume, wherein said audio volume is controlled to predetermined levels and a particular level provides optimum stereo separation, the method comprising the steps of:

demodulating an input signal in accordance with the desired volume level and outputting a volume controlled audio signal;

remodulating the volume controlled audio signal; and

indicating when the volume level of the audio signal provides optimum stereo separation.

25. Apparatus for use in a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels and a particular level provides optimum stereo separation, the apparatus comprising:

a demodulator for demodulating an input signal to provide an audio signal;

a modulator for modulating the volume controlled audio signal output of the volume control;

a volume control for varying the volume of the audio signal in accordance with the desired volume level and outputting a volume controlled audio signal; and

an indicator for indicating when the volume level of the audio signal provides optimum stereo separation.

26. A method for use in cable television converter apparatus for controlling the gain of a signal, wherein said gain is controlled to predetermined levels and a particular level attains an optimum condition, the method comprising the steps of:

inputting a desired gain level;

varying the gain of the signal in accordance with the desired gain level; and

indicating when the gain level of a the signal attains the optimum condition.

27. The method of claim 26, wherein the particular level attaining the optimum condition has unity gain through the apparatus.

28. The method of claim 26, further comprising the step of demodulating the signal prior to control of gain.

29. The method of claim 28, further comprising the step of remodulating the gain controlled signal.

30. The method of claim 26, further comprising the step of setting the gain to the particular level that attains the optimum condition.

31. The method of claim 30, wherein the optimum condition includes optimum stereo separation.

32. The method of claim 30, wherein the optimum condition includes nearly optimum signal-to-noise ratio and distortion.

33. The method of claim 26, further comprising the steps of:

enabling a peripheral control at a preprogrammed time; and

setting the gain control to the particular level that attains the optimum condition when the peripheral control is enabled.

34. The method of claim 33, wherein the particular level attaining the optimum condition has unity gain through the apparatus.

35. A method for use in a cable television converter, the method for calibrating an apparatus for controlling the gain of a signal, wherein said gain is controlled to predetermined levels and a particular level attains an optimum condition, the method comprising the steps of:

inputting a desired gain level for attainment of the optimum condition;

varying the gain of a gain control in accordance with the desired gain level; and

adjusting the gain of a trimming control until the optimum condition is met.

36. The method of claim 35, wherein the gain that attains the optimum condition has unity gain through the apparatus.

37. A method for use in a cable television converter, the method for calibrating an apparatus for controlling the gain of a signal, wherein said gain is controlled to predetermined levels and a particular level attains an optimum condition, the method comprising the steps of:

inputting a desired gain level for attainment of the optimum condition;

varying the gain of a gain control in accordance with the desired gain level;

adjusting the gain of a trimming control unitl the optimum condition is met, wherein the optimum condition includes optimum stereo separation, and the gain that attains the optimum condition has unity gain.

38. The method of claim 37, wherein the optimum condition further includes nearly optimum signal-to-noise ratio and distortion.

39. A method for use in a cable television converter apparatus, the method for controlling gain of a signal, wherein said gain is controlled to predetermined levels and a particular level attains an optimum condition, the method comprising the steps of:

storing the particular level in the apparatus;

enabling the appatatus at a predetermined time; and

setting the gain of the signal to the stored particular level that attains the optimum condition when the apparatus is enabled at the predetermined time.

40. A method for use in a cable television converter apparatus, the method for controlling gain of an audio signal, wherein said gain is controlled within a range of predetermined levels and a particular level attains an optimum condition, the method comprising the steps of:

storing the particular level in the apparatus, wherein said particular level is within said predetermined levels;

enabling the apparatus at a predetermined time; and

setting the gain of the audio signal to the stored particular level that attains the optimum condition when the apparatus is enabled at the predetermined time, wherein the optimum condition includes optimum stereo separation.

41. The method of claim 40, wherein the particular level attaining the optimum condition has unity gain.

42. The method of claim 40, wherein the optimum condition further includes optimum signal-to-noise ratio and distortion.

43. An apparatus for use in a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels, the apparatus comprising:

a switch having at least two states for enabling or disabling the converter in accordance with the state of switch;

a user interface for inputting a desired volume level regardless of the state of the switch; and

a volume control for varying the volume of an audio signal received by the converter in accordance with the desired volume level and outputting a volume controlled audio signal regardless of the state of the switch.

44. The apparatus of claim 43, further comprising a display for displaying the desired volume level regardless of the state of the switch.

45. An apparatus for use in a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels, the apparatus comprising:

a switch having at least two states for enabling or disabling the converter, said converter receiving an audio signal;

a user interface for inputting a desired volume level regardless of whether the converter is enabled or disabled by the switch;

a volume control for varying the volume of said audio signal delivered to said device in accordance with the desired volume level and outputting a volume controlled audio signal regardless of whether the converter is enabled or disabled by the switch; and

an indicator for indicating whe the volume level of the audio signal provides optimum stereo separation regardless or whether the converter is enabled or disabled by the switch.

46. The apparatus of claim 45, comprising a trimming control coupled to the volume control, the trimming control calibrated for a volume that provides optimum stereo separation when the desired volume level is at a particular level providing optimum stereo separation.

47. The apparatus of claim 46, wherein the volume that provides optimum stereo separation has unity gain through the apparatus.

48. The apparatus of claim 46, further comprising a demodulator for demodulating an input signal regardless of the state of the switch and providing the audio signal

49. An apparatus for use with a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels, the apparatus comprising:

a switch having at least two states for enabling or disabling the converter, said converter receiving an audio signal;

a user interface for inputting a desired volume level regardless of whether the converter is enabled or disabled by the switch;

a volume control for varying the volume of said audio signal delivered to said converter in accordance with the desired volume level and outputting a volume controlled audio signal regardless of whether the converter is enabled or disabled by the switch;

an indicator for indicating when the volume level of the audio signal provides optimum stereo separation regardless of whether the converter is enabled or disabled by the switch;

a trimming control coupled with the volume control, said trimming control calibrated for a volume that provides optimum stereo separation when the desired volume level is at a particular level providing optimum stereo separation;

a demodulator for demodulating an input signal regardless of whether the converter is enabled or disabled by the switch and providing the audio signal; and

a modulator for remodulating the volume controlled audio signal regardless of whether the converter is enabled or disabled by the switch.

50. An apparatus for use in a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels, the apparatus comprising:

a switch having at least two states for enabling or disabling the converter, said converter receiving an audio signal;

a user interface for inputting a desired volume level regardless of whether the converter is enabled or disabled by the switch; and

a volume control for varying the volume of said audio signal delivered to said converter in accordance with the desired volume level and outputting a volume controlled audio signal regardless of whether the converter is enabled or disabled by the switch;

a display for displaying the desired volume level regardless of whether the converter is enabled or disabled by the switch; and

an indicator for indicating when the volume level of the audio signal provides optimum stereo separation regardless or whether the converter is enabled or disabled by the switch.

51. A method for use with a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels, the method comprising steps of:

enabling or disabling the cable television converter, said converter receiving an audio signal;

inputting a desired volume level regardless of whether the converter is enabled or disabled by the switch;

varying the volume of said audio signal delivered to said converter in accordance with the desired volume level regardless of whether the coverter is emabled or disabled by the switch; and

indicating when the volume of the audio signal proves optimum stereo separation.

52. The method of claim 51, further comprising the steps of:

demodulating an input signal regardless of the state of the switch to provide the audio signal; and

remodulating the volume controlled audio signal regardless of the state of the switch.

53. The method of claim 51, further comprising the step of displaying the desired volume level regardless of the state of the switch.

54. A method for use in a cable television converter for controlling audio volume, wherein said audio volume is controlled to predetermined levels, the method comprising the steps of;

enabling or disabling the cable television converter, said converter receiving an audio signal;

inputting a desired volume level regardless of whether the converter is enabled or disabled by the switch;

varying the volume of said audio signal delivered to said converter in accordance with the desired volume level regardless of whether the converter is enabled or disabled by the switch;

displaying the desired volume level regardless of whether the converter is enabled or disabled by the switch; and

indicating when the volume level of the audio signal provides optimum stereo separation regardless of whether the converter is enabled or disabled by the switch.